Coherent control of nuclear spins in GaAs using spin injection techniques from a half-metallic spin source [an abstract of dissertation and a summary of dissertation review]Coherent control of nuclear spins in GaAs using spin injection techniques from a half-metallic spin source [an abstract of dissertation and a summary of dissertation review]ハーフメタル強磁性体からのスピン注入を用いたGaAsにおける核スピンのコヒーレント制御 [論文内容及び審査の要旨]